MEDICAL
HEART AND PERICARDIUM
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
V1-V6
|
|
|
I II III
|
|
|
AVL, AVR, AVF
|
|
|
None of the above
|
Detailed explanation-1: -Since the reference electrode has zero potential, the augmented potential represents only that measured by the three electrodes. The three augmented leads are designated aVR, aVL, and aVF. An impulse directed toward a limb lead records a positive or upright deflection in that lead.
Detailed explanation-2: -Unipolar leads (augmented leads and chest leads) have a single positive recording electrode and use a combination of the other electrodes to serve as a composite negative electrode. Normally, when an ECG is recorded, all leads are recorded simultaneously, giving rise to what is called a 12-lead ECG.
Detailed explanation-3: -These leads were originally constructed by Goldberger. In these leads the exploring electrode is compared with a reference which is based on an average of the other two limb electrodes. The letter a stands for augmented, V for voltage and R is right arm, L is left arm and F is foot.